Seal systems are used in a wide variety of rotary shaft devices, such as blowers, compressors, and pumps, which have critical sealing requirements. Dry gas seal systems provide a barrier between the gas in the working chamber, or process gas, and the external environment to minimize the loss of process gas to the environment. Seal systems may include two stages of seals arranged in tandem to improve reliability. Mosley and Haynes, in European Patent Application publication EP 0 701 074 A1, describe a dry gas seal with two face seal stages of the same construction.
Dry gas seals operate with very small gaps or separations between opposed sealing surfaces. Brittle materials such silicon or tungsten carbide are used for some sealing surfaces to provide precise surfaces for small separations between the opposed sealing surfaces. Such materials may, however, fail and a failure can be catastrophic.
The present disclosure is directed toward overcoming one or more of the problems discussed above as well as additional problems discovered by the inventor.